fix(parser): handle invalid surrogate pair as lossy (#9964)

- Closes #3526

It looks like invalid pair wasn't preserved properly. For example, `tasks/coverage/test262/test/built-ins/RegExp/escape/escaped-surrogates.js` has such code like this:

https://playground.oxc.rs/#eNplkU1TAjEMhv8K0wsXcAEFEceDCnjUgSuX0g1LtdvsJC0fw/Df7RKWccbT0ybp+ybNSRk1UQY9hxZ6aL202qtVnI57vfbzyks87PFPXNCv0yufZa2g+YczgzsgXUAWgMNgNLgwW0frQtd6zhZQzA5VBmx0BVfkXY5EWOhUe/fNjd3WFtvlLfFBGKv+f3/BQHAveBAMBSPBo2AseBK8Ct4E74KpYCaY1xOqjkI1OSmKvgYffdAHNQkUoaOc9UFNNtpxurDBCpoMH8s1uuYWSHveIJXX4nNHVZoYqJbUzuF+ASGS/4yBbQ7z6E2wmAzleUWQanfwpQk8SzRJ1O4XiXS+OYhm0FRAak0BD3r9YRrCMrr0m/kUjNOka/mk1HRjMIcCLhOC12sHS4xkoNTVza203m5s45cWFQjdPLVeP0qrXyOn6UXwfP4FSqrNaw==

input

```js
const one = '\uD800';
const two = '\uD800\uD801';

// tasks/coverage/test262/test/built-ins/RegExp/escape/escaped-surrogates.js
const highSurrogatesGroup1 = '\uD800\uD801\uD802\uD803\uD804\uD805\uD806\uD807\uD808\uD809\uD80A\uD80B\uD80C\uD80D\uD80E\uD80F';
```

output

```js
const one = '\uD800';
const two = "\\ud800\\ud801";
const highSurrogatesGroup1 = "\\ud800\\ud801\\ud802\\ud803\\ud804\\ud805\\ud806\\ud807\\ud808\\ud809\\ud80a\\ud80b\\ud80c\\ud80d\\ud80e\\ud80f";
```

crates/oxc_codegen/tests/integration/unit.rs

@@ -143,6 +143,7 @@ fn unicode_escape() {
     test("console.log('こんにちは');", "console.log(\"こんにちは\");\n");
     test("console.log('안녕하세요');", "console.log(\"안녕하세요\");\n");
     test("console.log('🧑‍🤝‍🧑');", "console.log(\"🧑‍🤝‍🧑\");\n");
+    test("console.log(\"\\uD800\\uD801\")", "console.log(\"\\uD800\\uD801\");\n");
 }
 
 #[test]

crates/oxc_parser/src/lexer/unicode.rs

@@ -136,11 +136,9 @@ impl<'a> Lexer<'a> {
                     self.token.lossy = true;
                 }
             }
-            SurrogatePair::HighLow(high, low) => {
-                text.push_str("\\u");
-                text.push_str(format!("{high:x}").as_str());
-                text.push_str("\\u");
-                text.push_str(format!("{low:x}").as_str());
+            SurrogatePair::HighLow(_high, _low) => {
+                text.push_str("\u{FFFD}\u{FFFD}");
+                self.token.lossy = true;
             }
         }
     }